The role of CEMENT in the 2050 LOW CARBON ECONOMY

Executive Summary

T H E E U R O P E A N C E M E N T A S S O C I AT I O N

Concrete is the third most used substance in the world after air and water, a staple of modern life and society.

CONCRETE ACTION for 2050

Concrete combines simplicity, durability, strength, affordability and infinite ability to be moulded. It provides the

solid foundations and essential built environment for society. Concrete is the third most used substance in the

world after air and water, a staple of modern life and society.

The special ingredient or glue which makes all this

possible is a rather ordinary-looking grey powder

called cement. Globally, cement production accounts

for around 5% of man-made CO2 emissions. The

industry recognises this responsibility and embraces

its commitment to reduce this markedly, especially

by contributing to the circular economy. In the

roadmap, we focused on what can be done to

reduce CO2 in cement production using today’s

technology, and will speculate on what could be

achieved by 2050.

As an industry, however, we will not focus only on

the solutions we provide, but also continue to act

responsibly to manufacture with maximum care. The

roadmap explores different routes and possibilities for

achieving a substantial reduction in CO2 emissions in

cement production. Moreover, their impact will not

be limited to reducing CO2 emissions, but can also

lead to a meaningful decrease in other greenhouse

gas emissions, as well as energy and use of natural

resources. We are confident that a combination of

parallel routes will result in a sustainable cement

industry in Europe.

A LOW-CARBON EUROPEAN CONCRETE and CEMENT SECTOR in 2050

The industry has focused on five routes to achieve

these objectives, three of which are considered to be

‘under the sector’s control’. Potential savings from

the other two routes outlined (Product Efficiency

and Downstream) do not relate directly to cement

manufacturing, so were not included. The sector

is committed, however, to investing in innovation

that explores new ways for cement and concrete to

contribute to a low carbon and circular economy,

especially where life cycle emissions of buildings and

structures can be meaningfully reduced by intelligent

use of concrete. This could increase the overall

contribution further.

The roadmap presents a vision for the sector whereby the cement carbon footprint could be reduced by 32%

compared with 1990 levels, using mostly conventional means. It also describes potential levers for how this could

be further increased by the application of emerging new technologies, such as carbon capture and storage (CCS).

Subject to specified policies and technological prerequisites, a potential reduction of up to 80% may be envisaged.

Only a combination of different ways to reduce

emissions, as set out in each of the chapters below,

can achieve substantial reductions.

■ Smart buildings & infrastructure development

■ Recycling concrete

■ Recarbonation

■ Sustainable construction

Downstream

■ Low carbon concrete

Product efficiency

■ Carbon sequestration and reuse

■ Biological carbon capture

Carbon sequestration and reuse

■ Electrical energy efficiency

■ Thermal energy efficiency

Energy efficiencyResource efficiency

■ Alternative fuels

■ Raw material substitution

■ Clinker substitution

■ Novel cements

■ Transport efficiency

The sector is committed to investing in innovation that explores new ways for cement and concrete to contribute to a low carbon and circular economy.

The source of our emissions in 1990

Building blocks and assumptions can be found on lowcarboneconomy.cembureau.eu

Our EMISSIONS

Multiple paths to emissions reduction

1990 emissions 170

Kiln efficiency and fuel mix 34136

Clinker substitution and Novel cements 11125

Transport efficiency 2123

Non C02 GHG 123

Decarbonisation power 10113

Breakthrough technologies 7934

2050 emissions 34

Combustion emissions (65,3 Mton CO2)

Non kiln fuels (1,5 Mton CO2)Transport fuels and raw materials (1,1 Mton CO2)

Emissions from power (9,8 Mton CO2)

Decarbonation emissions (92,4 Mton CO2)

Post factory transport (1,8 Mton CO2)

Our unique carbon profileThe cement and lime industries are unique due to the fact that the majority of greenhouse gas emissions

are not caused by energy use from fuel combustion, but come from the raw materials themselves. Around

60% of total CO2 emissions from clinker production are released directly from the processing of limestone.

Of the remaining 40%, most originate from burning fuel in the kiln to reach the high temperatures

necessary for clinker mineral formation. Indirect emissions from electrical power consumption contribute

approximately 6% to overall CO2 emissions.

CaCO3 + heat = CaO + CO2

The ability to mix fossil fuels like coal or gas with waste materials, biomass and industrial by-products is beneficial both from a resource efficiency and security of supply point of view.

FIVE PARALLEL ROUTES: Resource EfficiencyAlternative fuels

Alternative fuels, including a high proportion of

waste products, are increasingly being used and now

represent almost a third of all fuel in the EU cement

industry. The unique process and energy requirements

of the cement industry enable use of fuel mixes that

would not be suitable for many other industries. This

ability to mix fossil fuels like coal or gas with waste

materials, biomass and industrial by-products is

beneficial both from a resource efficiency and security

of supply point of view.

It has been estimated that by 2050, 40% of kiln energy

could potentially come from traditional sources, i.e. coal

(30%) and petcoke (10%), while 60% of kiln energy

could potentially be provided by alternative fuels of

which 40% could be biomass. This fuel mix would lead

to an overall decrease of 27% in fuel CO2 emissions.

Raw material substitution

The main raw material used in cement production

has traditionally been limestone. Limestone is

abundantly available, but over 60% of the industry’s

CO2 emissions are caused by transformation of

limestone into lime.

Limestone needed to make clinker can be partially

substituted by a range of alternative calcium

containing materials, including waste and industrial

by-products, which are already increasingly being

used. Moreover, many of the alternative materials are

ashes provided by the combustion of alternative fuels.

Clinker substitution

Ordinary Portland cement can contain up to 95%

clinker (the other 5% being gypsum). The current

average clinker-to-cement ratio over all cement types

in the EU27 is 73.7%1. The use of other constituents

in cement and the reduction of the clinker-to-cement

ratio means lower emissions and lower energy use.

Clinker can be blended with a range of alternative

materials, including pozzolans, finely ground limestone

and waste materials or industrial by-products.

However, varying clinker content has an impact on the

type of applications the cement can be used for.

There is a need to ensure that all the cement

manufactured is safe and durable as it will be used

in structures that are made to last at least 50 years

or more. Thus, high durability of the final product

concrete is a key property for sustainable construction.

There is some uncertainty regarding the future

availability of clinker substitutes (for example fly ash

supplied by coal fired power plants) as well as the

impact of environmental policy and regulation.

At a European level, it is estimated that the clinker-

to-cement ratio can be reduced to 70%, resulting in

a further CO2 saving of 4%.

Novel cements

The European cement industry is highly innovative

with large scale research centres in several countries

and hundreds of patents filed each year. A number

of low-carbon or very-low-carbon cements are

currently being developed. While some daunting

hurdles and validation of product properties remain,

there is ultimately the exciting prospect of entirely

new types of cement.

At a European level, it is estimated that the clinker-to-cement ratio can be reduced to 70%, resulting in a further CO2 saving of 4%.

1 Source: For the purposes of meaningful reporting, the definition of cement used in the GNR database differs slightly from that in common use. In this document, cement and cementitious products are considered equivalent.

There is a future for new or novel cement types, but

given the early stage of their development, it will

take quite some time before large-scale production

becomes a reality. Furthermore, they are likely to

be used in non-structural niche applications for

the foreseeable future. Nevertheless, a 5% share

of total cement production for novel cements has

been included, namely 11 million tonnes. Novel

cements will still require energy for their production

and will not be zero carbon products. The exact

potential carbon reduction is not known at this time

but for many of the more promising technologies,

it is estimated to be around 50%, which has been

applied in the modelling for the expected 5% of

total cement production.

Transport efficiency

Cement is a heavy product and so are its raw

materials. The industry is continuously working on

solutions to reduce transport related emissions and

expects to make significant progress on reducing

emissions related to heavy haulage by mixing water

and land based transport modes as well as improving

transport efficiency.

If the share of road transport is reduced to 50% by

2050, with both rail and water representing 23%

each, combined with innovation in the transport

sector, it has been estimated that transport related

emissions can be halved.

There is a future for new or novel cement types, but given the early stage of their development, it will take quite some time before large-scale production becomes a reality.

In a bid to increase its competitiveness, the European cement industry continuously strives to reduce power consumption and will continue to do so.

FIVE PARALLEL ROUTES: Energy EfficiencyElectrical energy efficiency

Cement production requires electric power at several

stages, from crushing of raw materials over clinker

production and cement grinding.

Continuous improvements to the production process

will lower the amount of electricity used. Replacing

older plants with more modern and efficient

technologies and continually modernising existing

plants will result in improved electrical performance.

However, deploying Carbon Capture technology

could increase electricity consumption by 50-120%.

The model included in this roadmap assumes

a total decarbonisation of the power sector by 2050

and all measures that will be taken to reduce our

electricity consumption do not have an impact on

the carbon profile of the calculations. Nevertheless,

the European cement industry continuously strives

to reduce power consumption and will continue to

do so.

Thermal energy efficiency

Cement manufacturing requires raw materials to be

heated to 1450°C and is thus rather energy intensive,

even if thermal energy only accounts for approximately

35% of the cement industry’s CO2 emissions.

Continuous improvements to production facilities

have almost halved our energy use since the 1960s.

Most European plants now use state-of-the-art

technology and the few remaining older wet

kilns will be replaced by more modern plants and

concentration of production in fewer, larger, plants

will lead to further reduced energy consumption.

Under optimised and regular conditions, the

best energy efficiency today – around 3,300 MJ/t

clinker – can be achieved with preheater kilns with

precalciners (PH-PC)

Taking into account the increased use of alternative

fuels, average thermal energy consumption per

tonne of clinker is expected to reach 3.3 MJ/tonne

by 2050.

Taking into account the increased use of alternative fuels, average thermal energy consumption per tonne of clinker is expected to reach 3.3 MJ/tonne by 2050.

FIVE PARALLEL ROUTES: Carbon sequestration and reuseCarbon Sequestration and Reuse

Even with the most efficient processes, a part of the

CO2 emissions linked to cement production cannot be

avoided. The possibility of carbon capture is currently

being evaluated in several large scale integrated CCS

(Carbon Capture and Storage) projects in the power

sector and the initial results show currently available

technologies could capture 90% of CO2 emissions.

Captured carbon could be transported to a storage

site or used in other production/downstream

processes e.g. to grow algae as biomass that can

be used as a fuel.

Carbon capture would increase production costs by

25 to 100%, require substantial investments and the

use of additional electricity. CCS is only realistic if the

CO2 transport infrastructure and storage sites are

suitable and approved for that purpose.

Carbon capture in the cement industry is still at the

research & development stage. Nevertheless, the

potential of CCS looks promising. In order to achieve

an 80% reduction in CO2 emissions by 2050, taking

into account all other measures, and without any other

breakthrough technology, 85% of all clinker production

would have to be equipped with carbon capture

technology, which amounts to 59% of all plants since

carbon capture would be deployed at larger plants.

Biological carbon capture

A promising alternative to CCS is using algae to

‘eat’ CO2 emissions and produce fuel at the same

time. Because of their substantial emissions, cement

plants would be ideally suited for deployment of this

innovative technology. Several projects, including

large-scale undertakings in Spain and France, are

currently underway to test the technology.

The algae can be harvested and dried (possibly using

waste heat from the cement plant), before being

used as a fuel for the cement kilns. Alternatively,

algae biomass can be processed into third-generation

biofuels, bio-plastics or high-value-added compounds

like antioxidants, lipids or proteins.

The technology is still at a very early stage of

development. Research projects will help to

determine the functional and economic feasibility of

industrial organic biomass production and how to

incorporate this technology into the manufacture

of cement.

Research projects will help to determine the functional and economic feasibility of industrial organic biomass production.

FIVE PARALLEL ROUTES: Product EfficiencyLow carbon concrete

After cement manufacturing, several techniques

and processes are used that further improve the

environmental performance of concrete. Techniques

include using high performance cements to optimise

cement use per tonne of concrete, locally sourcing

of aggregates, optimising admixtures and concrete

composition at the concrete mixing stage.

Modern high strength concretes can reduce the

volume of concrete needed to create a specific

structure. None of these have been included in

the CO2 reduction model as they do not relate to

reducing the impacts of cement manufacturing itself.

FIVE PARALLEL ROUTES: DownstreamCement is never used on its own. It is always mixed

with other materials to make plaster, mortar and most

importantly concrete. Therefore, the sector looks

beyond the factory gates and carries out research and

product development to improve the environmental

performance of concrete and how to reuse or recycle

concrete. None of the potential savings outlined in

these sections were included in our calculations.

Smart building and infrastructure development

Today, solutions exist for new buildings to be built

with 60% less energy use and CO2 emissions over

the life cycle than conventional buildings constructed

20 years ago.

Technology and new techniques in cement and

concrete can help extend the service life of buildings,

and improve their energy efficiency performance.

New buildings can be built with deconstruction rather

than demolition in mind and parts of buildings could

be re-used in their entirety or as modular elements.

Recycling concrete

About 200 million tonnes of construction and

demolition waste (C&DW) is generated every year in

Europe. Fortunately, at the end of its life cycle, concrete

can be recycled thus reducing its environmental impact.

The ‘zero landfill’ goal of concrete can be achieved if the

structure is carefully conceived and designed, and if the

building undergoes successful renovation or demolition.

Crushed concrete can be used as an aggregate

in concrete and the hardened cement fraction in

concrete can be recycled to raw material for cement

production. Crushed concrete can also be reused as

a foundation or backfilling for many applications.

Recarbonation

During the lifetime of a concrete structure (such

as a building or road), hydrated cement contained

within the concrete reacts with CO2 in the air. Part

of the CO2 emitted during cement production is re-

absorbed by the cement through carbonation,

a reaction also referred to as cement recarbonation.

Recarbonation mainly takes place at the surface.

Thus, if the structure can be deconstructed, crushed

concrete should be exposed to the air to enable the

full potential of recarbonation before it is used as a

foundation or backfiller.

Studies have been conducted to analyse the

recarbonation potential. They show that 5-20% of

the CO2 emitted during the cement manufacturing

process is taken up during the service life cycle of

concrete, and an additional 5-10% may be taken up

during the secondary or recycled lifetime.

Sustainable construction

Energy consumption of buildings is one of today’s

major environmental concerns, as buildings account

for approximately 35% of total EU greenhouse gas

emissions (including direct and indirect emissions

from electricity generation).

Concrete buildings can achieve considerable energy

savings during their lifetime because of the high

level of thermal mass they deliver, meaning that the

indoor temperature remains stable even when there

are fluctuations in temperature outside.

In the transport sector, which accounts for 20% of

total European greenhouse gas emissions, concrete

also contributes to reducing CO2 emissions in a

cost-effective way. According to studies, concrete

pavements can lower fuel consumption of heavy

trucks by up to 6% by reducing rolling resistance

between the road and the truck.

Concrete buildings can achieve considerable energy savings during their lifetime because of the high level of thermal mass they deliver

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www.cembureau.euThe full Roadmap is available at:

lowcarboneconomy.cembureau.eu

Comments on this roadmap are welcome and should be sent to Jessica Johnson (aj.johnson@cembureau.eu)

T H E E U R O P E A N C E M E N T A S S O C I AT I O N